Spring powered toothbrush



March 22, 1966 H. WINDWARD SPRING POWERED TOOTHBRUSH Filed March 25, 1964 United States Patent 3,241,169 SPRING POWERED TGOTHBRUSH Henry Windward, 2961 N. 44th St., Milwaukee, Wis. 53210 Filed Mar. 23, 1964, Ser. No. 353,818 Claims. (6]. 1522) This invention relates generally to power operated toothbrushes and more particularly to an improved selfcontained power operated toothbrush that is actuated by a spring powered motor.

Power operated toothbrushes in which the brush is reciprocated by a source of power have become increasingly popular and have been accepted as performing the dental cleaning function more efliciently than manually operated toothbrushes. This is particularly true because the proper cleaning motion can be readily achieved in a power operated toothbrush while such motion may be difficult to obtain manually. The primary disadvantage in power operated toothbrushes lies in their awkwardness to manipulate properly while cleaning teeth by reason of their connection to an independent source of power.

This type of toothbrush can be employed only when a suitable electric outlet is available for energizing the motor and the electric cord for transmitting the electric power to the motor interferes with the convenient manipulation of the appliance. In other arrangements an independent electric motor is provided with a flexible shaft connected from the drive shaft of the motor to the input shaft of the toothbrush for driving the latter. This design also requires a source of electric power for energizing the motor and the flexible shaft interferes with the manipulation of the apparatus during a teeth cleaning operation.

In an effort to overcome the above disadvantages, power operated toothbrushes have been produced with a selfcontained source of power in the form of a battery for energizing a direct current motor, all contained in the handle of the tooth brush. These have not proven to be entirely satisfactory due to lack of sufficient power for adequately driving the toothbrush, rapid deterioration of the battery requiring frequent replacement, or being too expensive to produce.

It is therefore a general object of the present invention to provide an improved power operated toothbrush.

Another object of the present invention is to provide a power operated toothbrush having an improved selfcontained power source.

Another object is to provide a power operated toothbrush with a self-contained mechanical source of power that is spring actuated to avoid the expense and annoyance of replacing batteries.

Another object is to provide a power operated toothbrush having a self-contained source of power which will furnish sufficient power for adequately driving the toothbrush to eiiiciently perform its intended function of cleaning teeth.

A further object is to provide a spring powered toothbrush equipped with an improved transmission and governor arrangement for automatically controlling the transmission of power from the spring to the toothbrush.

A further object is to provide a power operated toothbrush with a self-contained power unit of sturdy construction which is efficient and reliable in operation but inexpensive to produce and maintain.

According to this invention the improved power oper- 3,241,169 Patented Mar. 22, 1966 "ice ated toothbrush comprises a toothbrush having a drive mechanism supported in its handle with a power unit at the end of the handle for actuating the drive mechanism and its associated toothbrush. The power unit rotates an output shaft which is coupled to actuate the drive mechanism. The latter converts the rotary motion produced by the power unit to a reciprocating motion for actuating the toothbrush in a cleaning operation.

The power unit includes a coil spring contained within a housing. The spring may be wound to energize it by rotating a winding knob disposed at the end of the housing. After the spring is wound the energy produced by it is transmitted through a compact gear train contained in the housing for increasing the rate of rotation produced by the spring to prolong the dissipation of energy therefrom and the output of this transmission is regulated by a unique governor arrangement which controls the output of the spring to actuate the drive mechanism at a substantially uniform rate during the cleaning operation until the spring is almost completely unwound and the energy stored therein has been dissipated by the opera tion of the toothbrush.

The foregoing and other objects of the invention which will become more fully apparent from the following detailed specification setting forth an illustrative embodiment, may be achieved by the particular apparatus described in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a power operated toothbrush incorporating the features of the present invention.

FIGURE 2 is an enlarged view partly in side elevation and partly in section depicting the operating mechanism of the power unit of the toothbrush shown in FIGURE 1;

FIGURE 3 is a view partly in section and partly in elevation taken along the plane represented by the line 3-3 in FIGURE 2 to illustrate the ratchet mechanism for preventing a backward unwinding of the spring in the power unit;

FIGURE 4 is a view partly in section and partly in elevation taken along the plane represented by the line 44 in FIGURE 2 to illustrate a portion of the gear train;

FIGURE 5 is a View partly in section and partly in elevation taken along the plane represented by the line 5 -5 in FIGURE 2 to depict another portion of the gear train;

FIGURE 6 is a view partly in section and partly in elevation taken along the plane represented by the line 6- 6 in FIGURE 2 for showing another portion of the gear train;

FIGURE 7 is an enlarged detail view illustrating the governor that is shown mounted in the gear train in FIG. 6; and

FIGURE 8 is a' view partly in section and partly in elevation taken along the plane represented by the line 8-8 in FIGURE 7.

Reference is now made more particularly to the drawings and specifically to FIG. 1 thereof which illustrates a power operated toothbrush incorporating the features of the present invention. It comprises a toothbrush 10 mounted on the end of a shaft 11 that extends axially from a handle 12. The handle 12 contains a drive mechanism 13 that is actuated by a power unit generally identified by the reference numeral 15. The drive mechanism 13 operates to convert the rotary motion of an output shaft 16 of the power unit 15 into a reciprocating motion for oscillating the toothbrush 10 in a teeth cleaning operation. The construction and operation of the drive mechanism 13 is fully described in a co-pending 3 patent application of Karol Gerber et al., Serial No. 213,344 filed July 30, 1962, now Patent No. 3,133,297.

The power unit comprises a spring motor connected to actuate a gear train 21 that cooperates with a governor 25 for regulating the dissipation of the energy stored in the spring motor 21). The latter, along with the gear train 21 and its associated governor 25 are all enclosed in a cylindrical housing 26 that is secured to the lower end of the handle 12 by a nipple 27 which is fixed to the housing 26. The nipple 27 is in threaded engagement with the lower end of the handle 12 so that the latter extends axially from the power unit 15.

The spring motor 20 includes a coil spring 28 disposed within a drum 29 that is rotatably carried within the lower end of the housing 26. The interior end of the spring 28 is secured within a longitudinal slot 31 formed in a shaft that is rotatably supported within the housing 26. The spring 28 is wound about the shaft 38 and its exterior end is secured to the wall of the drum 29 by suitable rivets 32. The outer end of the drum 29 is closed by a circular plate 33 that is secured to the wall of the drum by screws 34. The shaft 30 extends through the plate 33 and is secured in position by a lock washer 40 located exteriorally of the plate 33 so that the shaft 30 can rotate relative to the plate 33.

The spring 28 is wound to energize it by rotating a winding knob 35 disposed exteriorally of the housing 26 at its lower end, with a portion of the winding knob 35 embracing the periphery of the housing 26 as clearly shown in FIG. 2. The winding knob 35 is fixed to the plate 33 by a plurality of screws 41 that extend through the winding knob 35 into threaded engagement with suitable holes provided in the plate 33. Accordingly, as the winding knob 35 is rotated by the operator, the plate 33 and its associated drum 29 rotate with it for winding the spring 28 about the shaft 30 which is prevented from rotating by a lock to be later described. A reverse rotation of the drum 29 is prevented by a ratchet mechanism generally identified by the reference numeral 45 and which is disposed between the inner end wall of the drum 29 and an inner end wall of a cylindrical enclosure 46 that contains the gear train 21 and is fixedly supported within the housing 26. The opposite end of the enclosure 46 is closed by a flange 47 formed integrally with the nipple 27.

The details of the ratchet mechanism 45 are illustrated in FIG. 3 and comprise a ratchet 48 that is secured to the inner end of the drum 29 by rivets 44 so that it rotates with the drum 29. During the winding of the spring to energize it the ratchet 48 rotates in a counterclockwise direction as viewed in FIG. 3, so that it notches pass by a pawl 49 that is pivotably supported by the inner wall of the enclosure 46. The pawl 49 is yieldably urged inwardly into engagement with the ratchet 48 by a spring 50 that is carried by a pin 51 which is likewise mounted on the inner wall of the enclosure 46. As the spring 28 is Wound about the shaft 30, of course, the spring urges the drum 29 in a direction to rotate the ratchet 48 in a clockwise direction as viewed in FIG. 3, but such rotation is prevented by the engagement of the notches of the ratchet 48 with the end of the pawl 49.

When the shaft 38 is released for rotation by the energized spring 28, it actuates the gear train 21 that drastically steps up the rate of rotation produced by the shaft 30 but the ultimate rate of rotation of the output shaft 16 is controlled by the operation of the governor 25. As a result, the dissipation of energy from the spring 28 is substantially prolonged to enable one winding of the spring to be sufficient for completing a cleaning operation. The arrangement of the gears in the gear train 21 are shown in FIGS. 2, 4, 5 and 6.

As shown in FIGS. 2 and 4, a gear 55 is keyed to rotate with the shaft 30 and is in meshing engagement with a gear 56 of a cluster that includes a larger gear 57. The gear cluster comprising the gears 56 and 57 are rotatable mounted on a shaft 58 that is supported within the enclosure 26. The gear 57 is in meshing engagement with a smaller gear 60 that is a member of a gear cluster which includes a larger gear 61. The gear cluster comprising the gears 60 and 61 is rotatably supported on a shaft 65 that is a reduced diameter extension of the shaft 30 for rotation therewith although the gears 60 and 61 will rotate relative to the shaft 65.

The large gear 61 is in meshing engagement with a smaller gear 66 that is part of a gear cluster which includes a larger gear 67. The gear cluster formed by the gears 66 and 67 is rotatably supported by a shaft 68 that is mounted within the enclosure 46. The large gear 67 is in meshing engagement with a gear 69 which is part of a gear cluster that includes a gear 7 0, the cluster being rotatably supported by the shaft 65. The gear 79, in turn, meshes with a smaller gear 71 of a gear cluster that includes a larger gear 72. The gear cluster comprising the gears 71 and 72 is rotatably supported by the shaft 58.

The large gear 72 is in meshing engagement with an idler gear 73 as illustrated in FIG. 6 and the idler gear 73, in turn, meshes with a gear 75 that is a part of the governor 25. The gear 75 meshes with another idler gear, not shown, which meshes with a gear 76 that is rotatably supported by the shaft 68 as illustrated in FIG. 2. The gear 76 is in meshing engagement with a gear 77 that is formed integrally with the output shaft 16 for rotating the latter. A stub shaft 78 extends ouwardly of the output shaft 16 and is secured to a spool 79 that is connected to actuate the drive mechanism 13. It is therefore apparent that the rotation of the shaft 30 by he spring 28 is transmitted through the gear train 21 for rotating the output shaft 16 and its associated stub shaft 78 for acuating the drive mechanism 13 to operate the toothbrush 10 in a cleaning operaion.

The construction of the governor 25 is illustrated in FIGS. 7 and 8. As there shown, the gear 7'5 which is rotated by the gear train 21 as previously described, is supported to rotate a shaft that carries a pair of parallel circular plates 86 and 87 which are fixed to rotate with the shaft 85. Each of the plates 86 and 87 is provided with a radial slot 88 to form a trackway for an iron slug 90 which is slidably carried by the trackway for radial movement with respect to the two parallel plates 86 and 87. A pin 91 is carried by the plates 86 and 87 to extend between them for supporting a spring 92 which has one end disposed about the shaft 85 and then extends around the pin 91 with a resilient portion engaging the iron slug 90 to yieldably urge the slug 96 toward the center of the plates 86 and 87.

The iron slug 90 cooperates with a permanent magnet 95 for governing the rate of rotation of the output shaft 16. The permanent magnet 95 is carried by a stop button 96 which is supported for sliding movement on the periphery of the cylindrical housing 26. The permanent magnet 95 shifts with the stop button 96 and carries a bar 97 for movement with it. The bar 97 extends downwardly to engage an extending end of the iron slug 90 for stopping the operation of the gear train 21 to prevent the rotation of the shaft 30 and thereby prevent unwinding of the spring 28. When the push button 96 is moved to the on position the bar 97 is moved out of engagement with the slug 90 to permit the plates 86 and 87 and their associated gear 75 to rotate relative to the permanent magnet 95. The rotation of the gear 75 and the plates 86 and 87 by operation of the spring 28 produce a centrifugal force which moves the iron slug 90 toward the outer end of the slots 88 against the force exerted by the spring 92 and toward the field of the stationery permanent magnet 95. As the iron slug 90 moves further into the field of the magnet 95 it cooperates with the magnetic field to produce a progressively increasing force which interferes with the rotation of the plates 86 and 87 to generate a progressively increasing load in the gear train. As a result, the rate of rotation of the gears in the train is reduced to thereby reduce the rate of dissipation of energy from the unwinding spring 28. As the rotation decreases to the desired rate, the slug 90 recedes toward the center of the plates 86 and 87 to permit the rotation of the output shaft 16 at the predetermined rate to produce the oscillation of the toothbrush at the desired frequency. With this arrangement, the increase in the rate for rotation produced by the gear train 21 in cooperation with the functioning of the governor 25 accurately regulates the dissipation of energy from the spring 28 to enable the toothbrush 10 to be actuated by the spring motor 20 with adequate force and at a predetermined frequency for a period of time suificient to complete a teeth cleaning operation with one Winding of the knob 35.

From the foregoing detailed description of the illustrative embodiment of the present invention, it will be apparent that a new and improved power operated toothbrush has been provided which utilizes a spring powered motor for actuating the toothbrush to avoid an exterior connection to a source of power, and the dissipation of energy frm the wound spring is accurately regulated by a gear train cooperating wit-h a unique governor arrangement especially adapted to perform in this capacity for prolonging the release of energy from the wound spring in the completion of the teeth cleaning operation.

Although the illustrative embodiment of the invention has been described in considerable detail for the purpose of making a full disclosure of a practical operative arrangement by means of which the invention may be practiced, it is to be understood that various novel features of the invention may be incorporated in other arrangements without departing from the spirit and scope of the invention as defined in the sub-joined claims.

The principles of the invention having now been fully explained in connection with the foregoing description Of embodying structure, I hereby claim as my invention:

1. In a power operated toothbrush; a brush; a spring motor; a gear train connected to transmit the power from Said spring motor to actuate said brush in a teeth cleaning operation, said gear train being adapted to progressively step up the rate of rotation produced by said motor; a trackway connected to be rotated by said gear train, said trackway extending radially from its axis of rotation; means producing a magnetic field adjacent to said trackway; and a magnetic element slidably supported by said trackway for movement toward said magnetic field in response to the centrifugal force produced by the rotation of said trackway to thereby progressively increase the resistance to rotation of said trackway and thereby limit the rate of rotation to a desired maximum for regulating the dissipation of energy from said spring motor.

2. In a power operated toothbrush; a brush; a spring motor; means connected to wind said spring motor for storing energy in it; transmission means connected to transmit the power from said spring motor to actuate said brush in a teeth cleaning operation; a trackway connected to be rotated by said transmission, said trackway extending radially from its axis of rotation; a magnetic element slidably supported by said trackway; means urging said magnetic element toward the axis of rotation of said trackway but yieldable to enable said magnetic element to move radially outwardly in response to the centrifugal force produced by the rotation of said trackway; and means producing a magnetic field adjacent to said trackway so that as said magnetic element moves outwardly in said trackway in response to the centrifugal force developed, it moves into said magnetic field to progressively increase the resistance to the rotation of said trackway and thereby limit its rate of rotation to a desired maximum for regulating the dissipation of energy from said spring motor.

3. In a governor for regulating the rate of rotation of a member; a trackway connected to be rotated by the member, said trackway extending radially from its axis of rotation; a slug formed of magnetic material slidably supported by said trackway; means urging said slug toward the axis of rotation of said trackway but yieldable to enable said slug to move radially outwardly in response to the centrifugal force produced by the rotation of said trackway; and means producing a magnetic field adjacent to said trackway so that as said slug moves outwardly in said trackway it moves into said magnetic field to increase the load opposing rotation and thereby limit the rate of rotation to a desired maximum.

4. In a governor for regulating the rate of rotation of a member; a magnetic element; supporting means connected to rotate with the rotation of the member; means producing a magnetic field adjacent to said supporting means; and a trackway carried by said supporting means for slidably supporting said magnetic element for movement toward said magnetic field in response tothe cenr trifugal force developed by the rotation of said supporting means so that as the rate of rotation of the member increases said magnetic element moves further into said magnetic field to produce a progressively increasing resistance to rotation of the member that limits its rate of rotation to a predetermined maximum.

5. In a governor for regulating the rate of rotation of a member; a magnetic element; means producing a magnetic field; and means supporting said magnetic element for movement toward said magnetic field in response to the centrifugal force produced by the rotation of said member so that as the rate of rotation of the member increases said magnetic element moves further into said magnetic field to produce a progressively increasing resistance to rotation of the member that limits its rate of rotation to a predetermined maximum.

References Cited by the Examiner UNITED STATES PATENTS 2,259,964 10/1941 Sussman 1523 3,029,651 4/1962 Flatt 15-22 X 3,115,652 12/1963 Zerbee 15-28 CHARLES A. WILLMUTH, Primary Examiner.

EDWARD L. ROBERTS, Assistant Examiner. 

5. IN A GOVERNOR FOR REGULATING THE RATE OF ROTATION OF A MEMBER; A MAGNETIC ELEMENT; MEANS PRODUCING A MAGNETIC FIELD; AND MEANS SUPPORTING SAID MAGNETIC ELEMENT FOR MOVEMENT TOWARD SAID MAGNETIC FIELD IN RESPONSE TO THE CENTRIFUGAL FORCE PRODUCED BY THE ROTATION OF SAID MEMBER SO THAT AS THE RATE OF ROTATION OF THE MEMBER INCREASES SAID MAGNETIC ELEMENT MOVES FURTHER INTO SAID MAGNETIC FIELD TO PRODUCE A PROGRESSIVELY INCREASING RESISTANCE TO ROTATION OF THE MEMBER THAT LIMITS ITS RATE OF ROTATION TO A PREDETERMINED MAXIMUM. 